People with fish-odor syndrome (trimethylaminuria) have an impaired version of the enzyme flavin-containing monooxygenase 3 (FMO3). This is the enzyme that converts trimethylamine to non-odorous trimethylamine N-oxide. Trimethylamine in breath can be also used in diagnostics of renal and liver diseases, and for real-time monitoring of haemodialysis efficiency.
One of the most important dietary sources of trimethylamine is choline found in most protein foods, especially eggs, liver, kidney, peas, beans, peanuts, soya products and cruciferous vegetables (brussels sprouts, broccoli, cabbage and cauliflower).
TMA N-oxide: Actinobacteria - Micrococcus and Mobiluncus; Firmicutes - Bacillus, Clostridium, Staphylococcus, Sarcina, Streptococcus, Alcaligenes; Proteobacteria - Campylobacter, Citrobacter, Escherichia, Proteus, Pseudomonas
Choline: Actinobacteria - Mobiluncus and Olsenella; Bacteroidetes - Bacteroides, Firmicutes - Anaerococcus, Clostridium, Desulfitobacterium, Enterococcus,
Streptococcus; Proteobacteria - Desulfovibrio, Edwardsiella, Escherichia, Klebsiella, Proteus,
Providencia, Pseudomonas, Yokenella
Carnitine: Proteobacteria - Acinetobacter, Citrobacter, Escherichia, Klebsiella, Proteus, Pseudomonas
Betaine: Firmicutes - Clostridium, Eubacterium, Sporomusa
Ergothioneine: Proteobacteria - Alcaligenes, Escherichia